From a471e7384d8d2e70073945e5a5e40749e6fa4c85 Mon Sep 17 00:00:00 2001
From: Ethan Atkins <contact@ethanatkins.com>
Date: Fri, 11 Sep 2020 10:50:20 -0700
Subject: [PATCH] Honor shellPrompt override

sbt 1.4.0 generates the shell prompt using the terminal properties for
the specific terminal for which the prompt is rendered. The mechanism
for doing this broke the prompt for projects that overrode the
shellPrompt key, notably the play plugin. After this change, the play
custom prompt is correctly rendered with 1.4.0-SNAPSHOT.
---
 .../src/main/scala/sbt/internal/ui/UITask.scala | 17 ++++++++++++-----
 main/src/main/scala/sbt/Defaults.scala          |  7 +++++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/main-command/src/main/scala/sbt/internal/ui/UITask.scala b/main-command/src/main/scala/sbt/internal/ui/UITask.scala
index f47def3a6..614fd05df 100644
--- a/main-command/src/main/scala/sbt/internal/ui/UITask.scala
+++ b/main-command/src/main/scala/sbt/internal/ui/UITask.scala
@@ -44,6 +44,9 @@ private[sbt] trait UITask extends Runnable with AutoCloseable {
 }
 
 private[sbt] object UITask {
+  case object NoShellPrompt extends (State => String) {
+    override def apply(state: State): String = ""
+  }
   trait Reader extends AutoCloseable {
     def readLine(): Either[String, String]
     override def close(): Unit = {}
@@ -93,11 +96,15 @@ private[sbt] object UITask {
   private[this] def history(s: State): Option[File] =
     s.get(historyPath).getOrElse(Some(new File(s.baseDir, ".history")))
   private[sbt] def shellPrompt(terminal: Terminal, s: State): String =
-    s.get(terminalShellPrompt) match {
-      case Some(pf) => pf(terminal, s)
-      case None =>
-        def ansi(s: String): String = if (terminal.isAnsiSupported) s"$s" else ""
-        s"${ansi(DeleteLine)}> ${ansi(ClearScreenAfterCursor)}"
+    s.get(sbt.BasicKeys.shellPrompt) match {
+      case Some(NoShellPrompt) | None =>
+        s.get(terminalShellPrompt) match {
+          case Some(pf) => pf(terminal, s)
+          case None =>
+            def ansi(s: String): String = if (terminal.isAnsiSupported) s"$s" else ""
+            s"${ansi(DeleteLine)}> ${ansi(ClearScreenAfterCursor)}"
+        }
+      case Some(p) => p(s)
     }
   private[sbt] class AskUserTask(
       state: State,
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index 3b37e8ad1..241b7e0c1 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -2558,9 +2558,12 @@ object Classpaths {
           val base = ModuleID(id.groupID, id.name, sbtVersion.value).withCrossVersion(cross)
           CrossVersion(scalaVersion, binVersion)(base).withCrossVersion(Disabled())
         },
-        shellPrompt := shellPromptFromState,
+        shellPrompt := sbt.internal.ui.UITask.NoShellPrompt,
         terminalShellPrompt := { (t, s) =>
-          shellPromptFromState(t)(s)
+          shellPrompt.value match {
+            case sbt.internal.ui.UITask.NoShellPrompt => shellPromptFromState(t)(s)
+            case p                                    => p(s)
+          }
         },
         dynamicDependency := { (): Unit },
         transitiveClasspathDependency := { (): Unit },